Digital World Tokyo: "Glasses superstore Megane Top has just started a handy service where browsers of the frame selection on their mobile website can go one step further and try them on virtually. This involves the would-be customers taking photos of themselves on the phone and combining them with shots of glasses downloaded from the Megane Top server." More details and pictures on the technology provider's site, in Japanese.

Or you can go low-tech and do what a glassware shop on Harvard Square in Cambridge is doing: snapping Polaroids as you try different frames.